Keycaps having reduced thickness

ABSTRACT

An illuminated glass keycap having a glyph diffuser layer that may diffuse light through a glyph window opened in a background layer. The background layer may be opaque and the glyph window may be transparent. The keycap is adhered to a scissor mechanism positioned above electrical switch circuitry. Included within, below, or adjacent to the scissor mechanism may be one or more light sources positioned to emit light through the keycap, around the perimeter of the keycap, and/or through the background layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/640,249, filed Jun. 30, 2017, and titled “Keycaps Having ReducedThickness,” which is a continuation of U.S. patent application Ser. No.14/502,788, filed Sep. 30, 2014, now U.S. Pat. No. 9,704,670, issuedJul. 11, 2017 and titled “Keycaps Having Reduced Thickness,” which is anon-provisional of and claims the benefit to U.S. Provisional PatentApplication No. 61/884,259, filed Sep. 30, 2013 and titled “KeycapsHaving Reduced Thickness,” the disclosures of which are herebyincorporated by reference herein in their entireties.

TECHNICAL FIELD

This disclosure relates generally to input apparatuses for computingdevices or other similar information processing devices and, inparticular, to thin profile keyboards.

BACKGROUND

A pleasing exterior appearance of an electronic device is oftendifficult to pair with the market demand for advanced functionality,improved durability, and reduced thickness and weight. Someaesthetically pleasing materials may not be sufficiently durable toinclude in a device housing and other aesthetically pleasing materialsmay interfere with the advance functionality of the electronic device.Further, for certain input components such as buttons and keys, a usermay physically engage the selected material several hundred thousandtimes, if not millions of times, over the life of a device.

Many visually pleasing solutions lack the durability for such extendedfunction. This can be especially true when electronic devices and/orassociated input devices are made smaller, thinner or otherwise reducedin dimension. Reduced dimensions of keycaps, for example, may lead tothose keycaps being less structurally sound and so breaking or otherwisefailing earlier during a use cycle than would thicker keycaps made ofthe same material.

Accordingly, there may be a present need for a durable and aestheticallypleasing external surface for an input device.

SUMMARY

This application provides techniques for forming and manufacturing anilluminated glass keycap for use with a key or keyboard as an inputapparatus to an electronic computing device. In certain embodiments, aninput apparatus may include a plurality of keys, each key of theplurality of keys including a transparent glass keycap having a topsurface, a background layer comprising a glyph window, a glyph diffuserlayer, a compressible scissor mechanism configured to activateelectrical switch circuitry, and a light source having an on state andan off state. The light source may be oriented to transmit light throughthe transparent glass keycap. In certain embodiments, the transparentglass keycap is comprised of glass. In certain cases the glass may be amaterial such as sapphire, a ceramic or another scratch resistantmaterial. Accordingly, the term “glass” may encompass such materials.The perimeter of the glass keycap may be beveled or otherwise polished.

Certain embodiments may relate to or take the form of an illuminatedinput apparatus having a glyph diffuser layer that may diffuse lightthrough a glyph window. In these embodiments, the background layer maybe opaque and the glyph window may be transparent. In other embodiments,the background layer may be translucent and the glyph window may betransparent. In further embodiments, the light source may be a lightemitting diode, a light emitting polymer, or a light pipe or othervisible light waveguide oriented to direct light through the transparentglass keycap.

Other embodiments described herein may relate to or take the form of anilluminated input apparatus having a light source including at least anon state and an off state. In certain cases, the on state may include akeycap perimeter illumination mode in which the light source may emitvisible light proximate or otherwise adjacent to the perimeter of thekeycap. In further embodiments, the on state may include a backgroundillumination mode in which the light source may transmit light throughthe background layer. In this case, the background layer may diffuse thetransmitted light before it exits the top surface of the transparentglass keycap. In further embodiments, the on state may include a glyphillumination mode in which the light source may transmit light through aglyph diffuser layer and further through the glyph window.

In other embodiments, the glyph diffuser layer is disposed partiallywithin the glyph window, such that at least a portion of the glyphdiffuser layer is coplanar with the background layer. In such anembodiment, or in similar embodiments, the glyph window may be etchedfrom the background layer.

Other embodiments described herein may relate to or take the form of amethod for manufacturing a light transmissive keycap for illuminating akeyboard, including the acts of selecting a transparent glass keycap,depositing a background ink layer on a bottom surface of the transparentglass keycap, etching a symbol aperture into the background ink layer,depositing a translucent glyph diffuser layer on the background ink overat least the symbol aperture, and aligning the transparent glass keycapalong a vertical axis with a compressible scissor mechanism positionedabove electrical switch circuitry. The method may also include bevelingthe perimeter edges of the transparent glass keycap.

Further embodiments may include positioning a light emitting elementbelow the transparent glass keycap such that light emitted from thelight emitting element transmits through the translucent glyph diffuserlayer and through the symbol aperture. In certain cases the symbolaperture may be etched in a laser etching process or, in otherembodiments, the symbol aperture may be formed by etching in a chemicalprocess.

Other embodiments described herein may relate to or take the form of akeyboard with a plurality of keys, each of the plurality of keys havinga keycap. Each keycap may include a glass top layer having at least fourbeveled edges along the perimeter of a top surface of the keycap, an inklayer disposed along a bottom surface of the glass top layer, a glyphwindow within the ink layer, and a diffuser fill within the glyphwindow. The keyboard may also include a light emissive layer, such as alayer of light emitting diodes, positioned below the keys. The keyboardcan also include an electrical switch layer that has a number ofelectrical switches, each associated with an individual key.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will now be made to representative embodiments illustrated inthe accompanying figures. It should be understood that the followingdescriptions are not intended to limit the embodiments to one preferredembodiment. To the contrary, it is intended to cover alternatives,modifications, and equivalents as may be included within the spirit andscope of the described embodiments as defined by the appended claims.

FIG. 1 is a perspective view of a sample embodiment of a sample keyboardfor use with an electronic device.

FIG. 2 is a partially exploded side cross-sectional view of a keycap andsupporting structure of the sample keyboard of FIG. 1, taken along line2-2 of FIG. 1.

FIG. 3A is a top plan view of a keycap showing a symbol as a portion ofthe embodiment as shown in FIG. 1.

FIG. 3B is a side view of the embodiment shown in FIG. 3A taken alongline 3B-3B.

FIG. 3C is a side view of the embodiment shown in FIG. 3A taken alongline 3C-3C.

FIG. 3D is a side view of the embodiment shown in FIG. 3A taken alongline 3D-3D.

FIG. 3E is a side view of the embodiment shown in FIG. 3A taken alongline 3E-3E.

FIG. 4A is an inverted side view of an embodiment showing a sample crosssection of a keycap after a background layer is applied.

FIG. 4B is an inverted side view of the embodiment shown in FIG. 4Ashowing a sample cross section of a keycap after a background layer hasbeen etched to expose portions of a glyph window.

FIG. 4C is an inverted side view of the embodiment shown in FIG. 4Bshowing a sample cross section of a keycap after a glyph diffuser layeris applied over the background layer and the exposed portions of a glyphwindow.

FIG. 4D is an inverted side view of the embodiment shown in FIG. 4Cshowing a sample cross section of a keycap after a glyph diffuser layeris drawn in to occupy the area of the glyph window.

FIG. 4E is an inverted side view of the embodiment shown in FIG. 4Dshowing a sample cross section of a keycap with the glyph diffuser layerfinished to a smooth plane, parallel with the planes of the keycap andthe background layer.

FIG. 4F is an inverted side view of the embodiment shown in FIG. 4Dshowing a sample cross section of a keycap with the glyph diffuser layerfinished to a smooth plane, coplanar with a surface of a backgroundlayer.

FIG. 5A is a top plan view of a keycap showing illumination of aperimeter portion, a glyph portion, and a background portion in an offstate.

FIG. 5B is a top plan view of a keycap showing illumination of aperimeter portion and a background portion in an off state with theillumination of a glyph portion in an on state.

FIG. 5C is a top plan view of a keycap showing illumination of abackground portion in an off state with the illumination of a perimeterportion and a glyph portion in an on state.

FIG. 5D is a top plan view of a keycap showing illumination of aperimeter portion, a glyph portion, and a background portion in an onstate.

FIG. 5E is a top plan view of a keycap showing illumination of a glyphportion in an off state with the illumination of a perimeter portion anda background portion in an on state.

FIG. 5F is a top plan view of a keycap showing illumination of a glyphportion and a perimeter portion in an off state with the backgroundportion in an on state.

FIG. 6 is a flow chart illustrating operations of a sample method formanufacturing an illuminated input apparatus.

The use of the same reference numerals in different drawings indicatessimilar, corresponding, or identical items.

DETAILED DESCRIPTION

Embodiments described herein may relate to or take the form oflight-transmissive and power efficient input apparatuses withlow-profile, durable external surfaces. In particular, certainembodiments may take the form of a fully or partially illuminatedkeyboard or keypad or individual key having glass keycaps. Such inputapparatuses may be used in conjunction with personal computing devicessuch as laptop computers, tablet computers, or desktop computers aseither integrated or peripheral devices. Certain other embodiments maytake the form of a fully or partially illuminated button with a glassouter surface for use with other electronic devices, such astelevisions, portable media players, cellular telephones, tabletcomputers, and the like.

One embodiment may be a back-illuminated key associated with a keyboard.The embodiment may include a glass keycap. The glass keycap can havebeveled or otherwise polished edges along a top surface. Disposedimmediately below the glass keycap may be a background layer formed ofink or another pigment, and may translucent, semi-transparent or opaque.In certain embodiments, the background layer may be applied to the glasskeycap in a printing process, a screening process, an immersion processor any other suitable process.

Etched into the background layer may be a glyph, symbol, window, oraperture (collectively, a “glyph window”). The glyph window may take theform of any numeral, symbol or letter of any language, or anyinformation-conveying symbol, appropriately suited to the input deviceas used. For example, the glyph window may take the form of an Englishletter or letters or symbols in one embodiment. In another embodiment,the glyph window may take the form of a simplified Chinese character orcharacters. The glyph window may be etched through the background layerby a laser scribing process, for example. In other embodiments, theglyph window may be etched via a mask and immerse chemical etchingprocess. In still further embodiments, the glyph window may not beetched at all, but may instead be provided by selectively applying abackground layer. For example, the background layer may be printed on asurface, such as a top or bottom surface, of the glass keycap in allareas except those reserved for the glyph window. In furtherembodiments, the glyph window may be formed within the background layerbefore the background layer is applied to the glass keycap.

A glyph diffuser layer may be disposed below the background layer. Theglyph diffuser layer may be formed of a semi-transparent or translucentmaterial that is doped with glass beads or another diffusion dopant. Incertain embodiments, the glyph diffuser layer may also include a pigmentor ink of a particular color. For example, in certain embodimentstitanium oxide may be used to give the glyph diffuser layer a whitecolor when light is transmitted through it. In certain furtherembodiments, the glyph diffuser layer may be disposed over thebackground layer with, and/or within the glyph window in a screening,printing, immersion, or any other suitable process. During theapplication of the glyph diffuser layer to the background layer,unwanted pockets of air may form within the glyph window, trapped by theapplication of the glyph diffuser layer. In order to remove the unwantedpockets of air, the keycap (with background layer and glyph diffuserlayer formed) may be placed in a vacuum chamber such that differentialpressure between the pockets and the vacuum cause the glyph diffuserlayer to remove the air pockets. In another embodiment, the keycap withbackground layer and glyph diffuser layer may be placed within anautoclave or other high pressure chamber to facilitate a pressuredifferential to remove the air pockets.

The glyph diffuser layer may be smoothed or polished to a plane in asubsequent process such that a bottom surface of the glyph diffuserlayer is substantially parallel with the top surface of the glasskeycap. Once smoothed, the keycap may be attached to a scissor mechanismand other elements of a key, in order to assemble the key. In certainembodiments, the glyph diffuser layer may be polished such that thebottom surface of the layer is coplanar with the bottom of thebackground layer. In other embodiments, the glyph diffuser layer may bepolished such that the bottom surface of the layer is parallel to, butseparated by, a specified depth from the bottom surface of thebackground layer.

Included within, below, or adjacent to the scissor mechanism may be oneor more light sources positioned to emit light through the keycap. Incertain embodiments, the light source may include or be coupled to alight source such as an organic light-emitting diode (OLED), alight-emitting diode (LED), or any other suitable light source. In afirst embodiment, the light source may be positioned to transmit lightthrough the glyph diffuser layer and through the glyph window. In suchan embodiment, the background layer may not transmit any of the lightemitted by the light source. In this way, when viewing the keycap fromabove, a glyph may be illuminated.

In a further embodiment, the light source may be positioned to transmitlight around the perimeter of the keycap. In this way, when viewing thekeycap from above the perimeter of the key (or an area around the keyperimeter) may be illuminated. In other words, the keycap may appear tohave a halo surrounding its periphery.

In a further embodiment, the light source may be positioned to transmitlight through the background layer. In such an embodiment, light may notnecessarily pass through the glyph window. In this way, when viewing thekeycap from above the background of a glyph may appear illuminated whilethe glyph itself remains dark.

FIG. 1 is a perspective view of a sample embodiment of an illuminatedkeyboard 100 for use with an electronic device (not shown). Theilluminated keyboard 100 may be a peripheral component of a computingsystem, or in other embodiments, it may be an integral portion of acomputing system. In further embodiments, the illuminated keyboard 100may have a greater number of keys or a fewer number of keys. The keysmay be arranged in various orders or configurations. The illuminatedkeyboard 100 may have one or more keys 110 and a housing 120 that fullyor partially encases the internal components of the keyboard. Each ofthe one or more keys 110 may have a glyph window 130 associated with it(e.g., visible on the keycap). As illustrated, the one or more keys 110may be of different sizes and/or positioned at different locations alongthe top surface of the illuminated keyboard 100.

FIG. 2 is a close-up and exploded side cross-sectional view of a key 200of an embodiment of the illuminated keyboard 100 of FIG. 1 taken alongline 2-2. The key 200 may be positioned at least partially within thehousing 220 of the illuminated keyboard 100. A key aperture 225 may bedefined through the housing 220. The key aperture 225 may be sized sothat a perimeter gap 230 exists between the key 200 and the housing 220.The perimeter gap 230 may be selectively sized based on the size of thekey 200. In certain embodiments, the key aperture 225 may not bepresent. Instead, one or more keys 110 (not shown in FIG. 2) may bearranged substantially adjacent to one another such that the perimetergap 230 of each key is defined by its neighboring keys.

The term “horizontal” as used herein and except as otherwise noted, isdefined as the plane parallel to the upper surface of the housing 220 ofthe illuminated keyboard 100. The term “vertical” as used herein andexcept as otherwise noted, is defined as the direction perpendicular tothe horizontal plane. Similar directional terminology as used herein(e.g., “above” or “below” or “top” or “bottom”) is defined with respectto the orientation of the keyboard shown in FIG. 1.

The key 200 may have a keycap 240. In certain embodiments, the keycap240 may be composed of silica glass (which may be chemically treated),sapphire, or another similar substantially transparent and scratchresistant material. The keycap 240 may have a substantially flat topsurface. In certain embodiments, the keycap 240 may have a slightlyconcave shape so as to enhance the feel of the key when depressed by auser. The top surface of the keycap 240 may have one or more bevelededges 242. A beveled edge 242 may be angled at a 45 degree angle asshown, or in some embodiments, the beveled edge 242 may be machined suchthat it takes another shape that reduces or increases the angle formedby the top and sidewalls of the keycap 240 along its perimeter.

A substantially opaque background layer 250 may be formed on anunderside of the keycap 240. The background layer 250 may define a glyphwindow 260 extending through the background layer. Although shown incross section, one may appreciate that the glyph window 260 may, whenviewed from above, take the form of any numeral, symbol or letter of anylanguage or symbol set appropriately suited to the illuminated keyboard100 (not shown in FIG. 2). Essentially, the portions of the underside ofthe keycap 240 that are not coated, treated, or otherwise covered withthe background layer may form the glyph window 260. As the glyph windowmay correspond to a letter, symbol, character, number and the like, itmay vary in size, shape and cross-section from keycap to keycap.Further, some keycaps may lack any glyph window at all; the space bar isone example of this.

A glyph diffuser layer 270 may be formed on the underside of thebackground layer 250 and may fill (either partially or fully) the glyphwindow 260. The glyph diffuser layer 270 may be composed of asemi-transparent or translucent material that is doped with a diffusiondopant. In certain embodiments, the glyph diffuser layer 270 may also bedoped with a colored pigment to color the layer. As one example,titanium oxide may be used to give the glyph diffuser layer a whiteappearance. The glyph diffuser layer 270 may also include complementarygeometry to the glyph window 260. In this way, the glyph diffuser layer270 may occupy the volume of the glyph window 260 within the backgroundlayer 250.

A mechanical support may be positioned beneath and attached to thekeycap. For example, a scissor mechanism 284 or butterfly mechanism maybe affixed to a keycap receiving pad 280. The receiving pad 280 may beadhered or otherwise bonded to the glyph diffuser layer 270. The keycapreceiving pad 280 may include a structure such as a detent, ledge oraperture to accept one or more top crossbars forming part of a scissormechanism 284.

In more detail, the keycap receiving pad 280 may have a substantiallyflat top surface and may be adhered or attached to the bottom surface ofthe glyph diffuser layer 270.

A membrane 282 of a dome switch may be positioned below the keycapreceiving pad 280. In some embodiments, the membrane 282 may contact thebottom surface of the keycap receiving pad 280 when the key is in aneutral (e.g., unpressed) state, while in other embodiments the membrane282 and keycap receiving pad 280 may be separated by an air gap when thekey is in a neutral state. The membrane 282 may be constructed of adeformable material such as rubber, silicone, or any suitable polymerand may include one or more electrical contacts (not shown in thecross-section of FIG. 2). In some embodiments the membrane 282 may besubstantially transparent, while in others the membrane may betranslucent or opaque. In some embodiments, light may be transmitted toor through the keycap from a light source located to a side of the key,such as an LED or a light pipe connected to an LED.

Adjacent to the membrane 282 may be a compressible scissor mechanism284. Below the membrane 282 may be a first contact wiring layer 286.Electrical contacts (not shown in the cross-section view of FIG. 2) maybe disposed on the top surface of the first contact wiring layer 286such that when the membrane 282 and the compressible scissor mechanism284 compress beyond a selected threshold, the electrical contacts of themembrane 282 and the electrical contacts of the first contact wiringlayer 286 complete an electrical circuit and thereby signal that the key200 has been depressed.

The first contact wiring layer 286 may be disposed upon a firstsubstrate layer 288 to provide structural support to the key 200. Thesubstrate layer 288 may be composed of a transparent or substantiallytransparent material. Below the substrate layer 288 may be anillumination layer 290 including a light emitting element 292 which iscentered below the keycap 240. The light emitting element 292 may be anLED, OLED, or any other suitable light source. Although shown as asingle light source, one may appreciate that multiple light sources maybe used. For example, a light emitting element 292 may be positioned onthe illumination layer 290 so as to direct or transmit light through theperimeter gap 230. In this manner, the light emitting element 292 mayilluminate the perimeter of the key 200, creating a halo effect aboutthe key 200 when viewed from above.

In another embodiment, a light emitting element 292 may be positioned todirect light only through the glyph window 260. In this manner, thelight emitting element 292 may illuminate the glyph window 260, creatingan illuminated glyph effect on the surface of the key 200 when viewedfrom above.

In another embodiment, a light emitting element may be positioned todirect light only through the background layer 250. In this manner, thelight emitting element 292 may illuminate the background area around theglyph window, leaving the glyph window area unilluminated. In such anembodiment, one may appreciate that the background layer 250 may becomposed of a semi-transparent or translucent material. For example, inthis embodiment the background layer 250 may be composed of asemi-transparent or translucent material that is doped with glass beadsor other diffusion dopant.

One may further appreciate that a plurality of light emitting elements292 may be disposed upon or within the light emissive layer 290. In thismanner, multiple portions of the key 200 may be selectively or jointlyilluminated. Below the light emissive layer 290 may be disposed a secondsubstrate layer 294, providing structural support to the key 200.

One may appreciate that FIG. 2 is not necessarily drawn to scale. Forclarity, the relative height of each illustrated item has in some casesbeen exaggerated to show the relationship between each of the severallayers forming key 200. For example, the background layer 250 and theglyph diffuser layer 270 may only be a few microns in height. Further,one may appreciate the keycap 240 may be less than a millimeter inheight.

FIG. 3A is a top plan view of a keycap 300 showing a glyph as a portionof the embodiment as shown in FIG. 1. The keycap may include at leastbackground area 310 and a glyph area 315, which as illustrated shows theEnglish letter “A.” The keycap 300 may be situated within the housing320 of an illuminated keyboard 100 (now shown, see FIG. 1). The keycap300 may be positioned within a key aperture 325. The horizontal surfacearea of the key aperture 325 may be slightly larger than the horizontalsurface area of the keycap 300 such that a keycap perimeter gap 380 isexposed.

FIGS. 3B-3E are close up side views of the embodiment shown in FIG. 3Ataken along cross sections 3B-3E respectively. Visible in all four crosssections shown in FIGS. 3B-3E is the keycap 340. The keycap 340 sitswithin a key aperture (not labeled) formed in the keyboard housing 320.A perimeter gap 330 is formed between the edges of the key aperture andthe keycap. As noted with respect to the embodiment illustrated by FIG.2, the keycap 340 may be composed of glass and may have beveled orpolished edges.

Visible in all four cross sections shown in FIGS. 3B-3E is thebackground layer 350. Also as noted with respect to the embodiment shownin FIG. 2, the background layer 350 may be disposed directly below theglass keycap 340. Disposed below the background layer 350 is the glyphdiffusion layer 370.

One may appreciate that line 3B-3B of FIG. 3A may not intersect anyportion of the glyph area 315 of FIG. 3A. Accordingly, in thecross-section shown in FIG. 3B, no portion of a glyph window is presentor illustrated. However, line 3C-3C of FIG. 3A does intersect a portionof the glyph area 315 of FIG. 3A. Specifically, line 3C-3C intersectsthe crest of the “A” glyph as illustrated in FIG. 3A. Accordingly,within the cross section shown in FIG. 3C, a portion of a glyph window360 is shown. Because line 3C-3C intersects the glyph window only once,FIG. 3C illustrates only a single portion of the glyph window 360.

FIG. 3D is a close up side view of the embodiment shown in FIG. 3A takenalong line 3D-3D, which intersects both legs of the letter “A,”illustrated as the glyph area 315 in FIG. 3A. Accordingly, in crosssection FIG. 3D illustrates two portions of the glyph window 360separated by a portion of the background layer 350.

Similar to FIG. 3B, FIG. 3E does not intersect any portion of the glypharea 315 of FIG. 3A and accordingly, no portion of a glyph window ispresent or illustrated.

With respect to FIGS. 4A-4D, the term “horizontal” is defined as theplane parallel to the surface of the glass keycap. The term “vertical”as with respect to FIGS. 4A-4D is defined as the direction perpendicularto the horizontal plane. Similar directional terminology as used herein(e.g., “above” or “below” or “on” or “under”) is defined with respect tothe horizontal plane.

FIG. 4A is an inverted close up side view of an embodiment showing asample cross section of a keycap 440 after a background layer 450 isapplied. The background layer 450 may be composed of ink or pigment, andmay be translucent, semi-transparent or opaque. In certain embodiments,the background layer 450 may be applied to the glass keycap 440 in aprinting process, a screening process, an immersion process or any othersuitable process.

FIG. 4B is an inverted close up side view of the embodiment shown inFIG. 4A showing a sample cross section of a keycap 440 after abackground layer 450 has been etched to expose portions of a glyphwindow 460. The glyph window 460 may be etched through the backgroundlayer in a laser-scribing process. For example, a laser may ablate thebackground layer 450 in order to expose the glyph window 460. In certaincases, the laser may be sufficiently powerful to ablate or otherwiseremove the material of the background layer 450 while beinginsufficiently powerful to ablate or otherwise etch or damage thematerial selected for the keycap 440.

In other embodiments, the glyph window 460 may be etched with a chemicaletching process. For example, a mask may be applied over the backgroundlayer 450. The mask may cover portions of the background layer 450 thatwill remain after etching, but may expose all portions of the backgroundlayer 450 that should be removed in order to expose the glyph window460. After the mask is applied, the keycap 440 and background layer 450may be immersed in or exposed to an etching solution that dissolves orotherwise reacts with the material selected for the background layer 450but not the material selected for the mask or the material selected forthe keycap 440. After a proscribed period of time, the keycap 440 may beremoved from the etching solution and the mask may be removed from thebackground layer 450.

In still further embodiments, the glyph window 460 may not be etched atall, but may instead be formed by selectively applying background layer450. For example, the background layer 450 may be printed along thesurface of the glass keycap 440 in all areas except those reserved forthe glyph window 460.

FIG. 4C is an inverted close-up side view of the embodiment shown inFIG. 4B, showing a sample cross section of a keycap 440 after a glyphdiffuser layer 470 is applied over the background layer 450 and theexposed portions of a glyph window 460. In certain embodiments, duringthe application of the glyph diffuser layer 470 to the background layer450, unwanted pockets of air 490 may remain within the glyph window 460.The unwanted pockets of air 490 may cause undesirable visual artifactsin the keycap 440.

In order to remove the unwanted pockets of air 490, the keycap 440 (withbackground layer 450 and glyph diffuser layer 470 already formed) may beplaced in a vacuum chamber (not shown) such that a negative pressuredifferential forms to eliminate the air pockets 490. Generally, airpockets 490 may be created at or near atmospheric pressure. Accordingly,when placed in a vacuum environment, the pressure of the air pockets 490may equalize with the vacuum, which may pull the diffuser layer 470 into fill the entire volume of the glyph window 460, as shown in FIG. 4D.

In another embodiment, the keycap 440, with background layer 450 andglyph diffuser layer 470, may be placed within an autoclave or otherhigh pressure chamber to facilitate a positive pressure differential toremove the air pockets 490. As noted above, the air pockets 490 may becreated at or near atmospheric pressure. When placed in a high pressureenvironment, the difference in pressure may push the diffuser layer 470to fill the entire volume of the glyph window 460, as shown in FIG. 4D.

FIG. 4E is an inverted close up side view of the embodiment shown inFIG. 4D showing a sample cross section of a keycap 440 with the glyphdiffuser layer 470 finished to a smooth plane, parallel with the planesof the keycap 440 and the background layer 450. Once polished orotherwise smoothed, the glyph diffuser layer 470 may be attached to ascissor mechanism (not shown) or other button mechanism positioned toactivate electrical switch circuitry when depressed. The glyph diffuserlayer 470 may be smoothed in order to provide a substantially parallelrelationship between the scissor mechanism and the top surface of thekeycap 440.

FIG. 4F is an inverted close-up side view of the embodiment shown inFIG. 4D showing a sample cross section of a keycap 440 with the glyphdiffuser layer 470 finished to a smooth plane that is coplanar with asurface of a background layer 450. In certain embodiments, smoothing theglyph diffuser layer in this manner may provide for an exceptionallythin overall key thickness.

One may appreciate that FIGS. 3A-4F are not drawn to scale. For clarity,the relative height of each illustrated item has in some cases beensubstantially exaggerated to show the relationship between each of theseveral layers forming the illustrated key. For example, one mayappreciate that the background layer 350 and 450 and the glyph diffuserlayer 370 and 470 may only be a few microns in height. Further, one mayappreciate the keycap 340 and 440 may be less than a millimeter inheight.

FIGS. 5A-5F illustrate various configurations of selective a jointillumination of individual portions of a key according to one embodimentof the invention.

FIG. 5A is a top plan view of a keycap showing the selectiveillumination of a perimeter gap portion 580, a glyph area portion 515(not shown), and a background area portion 510 in an off state. One maynote that in the illustrated embodiment, a glyph portion 515 is notvisible. In certain embodiments, the boundaries between the backgroundportion 510 and the glyph area portion 515 are not distinguishable.Accordingly, FIG. 5A is illustrated without the glyph area visible.

FIG. 5B is a top plan view of a keycap showing illumination of aperimeter gap portion 580 and a background area portion 510 in an offstate with the illumination of a glyph area portion 515 in an on state.

FIG. 5C is a top plan view of a keycap showing illumination of abackground area portion 510 in an off state with the illumination of aperimeter gap portion 580 and a glyph area portion 515 in an on state.In this manner, FIG. 5C illustrates a glyph illumination mode of thekeycap.

FIG. 5D is a top plan view of a keycap showing illumination of aperimeter gap portion 580, a glyph area portion 515 (not shown), and abackground area portion 510 in an on state. As noted above with respectto FIG. 5A, the glyph portion 515 is not visible. In certainembodiments, the boundaries between the background portion 510 and theglyph area portion 515 are not distinguishable. Accordingly, FIG. 5D isalso illustrated without the glyph area visible. In this manner, FIG. 5Dillustrates a perimeter illumination mode of the keycap.

FIG. 5E is a top plan view of a keycap showing illumination of a glypharea portion 515 in an off state with the illumination of a perimetergap portion 580 and a background area portion 510 in an on state. Inthis embodiment, the glyph area 515 may visible to a user as a shadowand the background area portion 510 and the perimeter gap portion 580may appear as a singular or substantially singular illuminated area.

FIG. 5F is a top plan view of a keycap showing illumination of a glypharea portion 515 and a perimeter gap portion 580 in an off state withthe background area portion 510 in an on state. In this embodiment, theglyph area 515 may visible to a user as a shadow within the illuminatedbackground area portion 510. The darkened perimeter gap portion 580 mayprovide enhanced contrast with the background area 510. In this manner,FIG. 5F illustrates a background illumination mode of the keycap.

Although FIGS. 5A-5F illustrate various combinations of illuminatedportions of a keycap, one may appreciate that additional or fewercombinations are contemplated. One may appreciate further thatindividual keys on the same keyboard may be illuminated separately,sequentially, with differing brightness, for varying durations, etc.

FIG. 6 is a flow chart illustrating operations of a sample method formanufacturing an illuminated input apparatus. At 610, a glass keycap maybe selected. In certain embodiments, the glass keycap may be singulatedfrom a larger sheet or, in other embodiments a large mother sheetcontaining a plurality of individual glass keycaps to be singulated in alater process.

At 620, a background layer may be deposited on the glass keycap. Incertain embodiments, the background layer may be applied to the glasskeycap in a printing process, a screening process, an immersion processor any other suitable process. In certain embodiments, the backgroundlayer may be cured before other operations continue.

At 630, a glyph window may be etched into the background layer. Theglyph window may be etched in a laser etching process, or in otherembodiments, the glyph window may be formed by etching in a chemicalprocess. The glyph window may take the form of any numeral, symbol orletter of any language appropriately suited to the keycap. One mayfurther appreciate that in certain embodiments, operations 620 and 630may be accomplished simultaneously if the background layer is applied ina printing process.

At 640, a diffuser layer may be applied to the background layer. Thediffuser layer may be composed of a semi-transparent or translucentmaterial that is doped with glass beads or other diffusion dopant. Thediffuser layer may be disposed over the background layer with glyphwindow in a screening, printing, immersion, or any other suitableprocess.

At 650, the glass keycap, background layer, and diffuser layer may beplaced in curing conditions in order to solidify or otherwise bond thelayers together. Curing conditions may include but are not limited to anultraviolet oven, a heated oven, a vacuum chamber, or an autoclavechamber. The curing process may include processes to remove unwanted airpockets from either the background layer or the diffuser layer.

At 660, the diffuser layer may be polished or otherwise finished to aplane substantially parallel to the top surface of the glass keycap. Theprocess may conclude at 670.

One may appreciate that although many embodiments are disclosed above,that the operations presented in FIG. 6 are meant as exemplary andaccordingly are not exhaustive. One may further appreciate thatalternate step order, or additional or fewer steps may be used toaccomplish methods contemplated here.

Where components or modules of the invention are implemented in whole orin part using software, in one embodiment, these software elements canbe implemented to operate with a computing or processing module capableof carrying out the functionality described with respect thereto.

Embodiments have been described herein with respect to glass keycaps,but it should be appreciated that structures, methods, processes,apparatuses and the like may employ, operate with, be incorporated intoor otherwise associated with keycaps and/or keys made from othermaterials. For example, certain embodiments may use a metal keycap, aceramic keycap, a polymer keycap, and so on.

Although the disclosure above is described in terms of various exemplaryembodiments and implementations, it should be understood that thevarious features, aspects and functionality described in one or more ofthe individual embodiments are not limited in their applicability to theparticular embodiment with which they are described, but instead can beapplied alone or in various combinations to one or more of the otherembodiments of the invention, whether or not such embodiments aredescribed and whether or not such features are presented as being a partof a described embodiment. Thus, the breadth and scope of the presentinvention should not be limited by any of the above-described exemplaryembodiments but is instead defined by the claims herein presented.

We claim:
 1. A keyboard for a laptop computer, the keyboard comprising:a key comprising: a keycap comprising an at least partially transparentmaterial, the at least partially transparent material having a bottomsurface; a background ink layer disposed on the bottom surface of the atleast partially transparent material and defining a glyph window havinga side surface, the background ink layer comprising a bottom surface anda top surface; and a glyph diffuser contacting the side surface of theglyph window between the top surface and the bottom surface of thebackground ink layer and having a bottom surface coplanar with thebottom surface of the background ink layer; a substrate positioned belowthe key; a switch positioned between the substrate and the key; asupport mechanism configured to support the key while the key isdepressed by a user relative to the substrate.
 2. The keyboard of claim1, wherein the background ink layer comprises a top surface and theglyph diffuser comprises a top surface, the top surface of the glyphdiffuser being coplanar with the top surface of the background inklayer.
 3. The keyboard of claim 1, wherein the glyph diffuser fills anentire volume of the glyph window.
 4. The keyboard of claim 1, whereinthe bottom surface of the glyph diffuser is parallel to a bottom surfaceof the keycap.
 5. The keyboard of claim 1, wherein the bottom surface ofthe glyph diffuser is parallel to a top surface of the keycap.
 6. Thekeyboard of claim 1, wherein the keycap comprises a concave top surface.7. The keyboard of claim 1, wherein the background ink layer is opaqueand the glyph diffuser is at least partially transparent.
 8. Thekeyboard of claim 1, further comprising a receiving pad attached to theglyph diffuser and coupled with the support mechanism.
 9. The keyboardof claim 8, wherein the receiving pad is configured to contact theswitch when the key is depressed by the user.
 10. The keyboard of claim8, wherein the receiving pad is separated from the switch by an air gap.11. A method of manufacturing a keycap, the method comprising:depositing a background ink layer on a bottom surface of the keycap, thekeycap comprising an at least partially transparent material; creating aglyph aperture through the background ink layer, the glyph aperturehaving a lateral width, wherein the keycap is at least partially exposedthrough the background ink layer; depositing a glyph diffuser materialinto the glyph aperture between a top surface of the background inklayer and a bottom surface of the background ink layer and filling thelateral width of the glyph aperture; planing the glyph diffuser materialsuch that a bottom surface of the glyph diffuser material is coplanarwith the bottom surface of the background ink layer.
 12. The method ofclaim 11, wherein the glyph diffuser material is deposited into theglyph aperture under vacuum conditions.
 13. The method of claim 11,wherein negative pressure pulls the glyph diffuser material into theglyph aperture.
 14. The method of claim 11, wherein the glyph diffusermaterial fills an entire volume of the glyph aperture.
 15. The method ofclaim 11, wherein planing the glyph diffuser material comprises removingglyph diffuser material located below the bottom surface of thebackground ink layer.
 16. The method of claim 11, further comprisingforming a top surface of the glyph diffuser material to be coplanar withthe bottom surface of the keycap.
 17. The method of claim 11, furthercomprising attaching a receiving pad to the glyph diffuser material orto the background ink layer.
 18. A keycap for a keyboard of anelectronic device, the keycap comprising: a transparent body having atop surface and a bottom surface, the top surface being at leastpartially concave; a background layer formed on the bottom surface ofthe transparent body, the background layer defining a glyph shape; adiffuser layer configured to distribute light through the backgroundlayer or the glyph shape, the diffuser layer being positioned on anunderside of the background layer and abutting sides of the glyph shapeof the background layer, the diffuser layer being configured to link thebackground layer to a key support mechanism.
 19. The keycap of claim 18,wherein the transparent body comprises a glass or sapphire material. 20.The keycap of claim 18, wherein the transparent body includes a bevelededge.